Parallelism improves glass manufacturing competitiveness

Barcelona, 13-6-97 Glasspar is a project developed at the University of Cantabria with a double objective. On the one hand, the project looks for a physical model that describes a specific process of glass fabrication on an industrial scale and, on the other, it intends to implement the model in a parallel platform to allow modelling of different production prototypes. Parallelism is a good and cheap option for glass manufacturers that need large amounts of calculation. The project has a clear industrial benefit, as it is aimed to increase enterprises' capacity of design and product quality and thus enhance competitiveness.

The partners of the Project are: Cristaler a Espanola S.A. (CESA), University of Cantabria (the Architecture and Computer Technology group, the Oceanographic and Coastal Engineering group, the Geographic Engineering and Graphic Expression Techniques Department) and the European Centre for Parallelism of Barcelona (CEPBA). Glasspar was set up in April 1996 and is scheduled to be completed next September. The project belongs to the PCI-II initiative of the ESPRIT-IV program and has a budget of nearly 32 millions of pesetas.

The full process has been studied at CESA's production plant in Avilas (Asturias). The glass paste is formed in a furnace where the different components are warmed up and mixed. The result is a fluid at more than 1000 °C which is poured into a barrel containing liquid tin. The glass layer floats over the tin layer (denser than glass) while it is being stretched and solidified and is taken out of the barrel at less than 700 °C. This phenomenon of dragging down the glass across the barrel induces streams inside the bed of liquid tin.

These streams involve a mass transport of the tin located within areas of different temperatures and, therefore, determines the final thermic map that will be decisive in the mechanical, planimetric and optical conditions of the final glass. The aim of the project is to build a mathematical model that simulates the hydrodynamic and thermic phenomena that determine the barrel status and the interaction between tin and glass layers. The mathematical model developed by the Oceanographic and Coastal Engineering group of the University of Cantabria solves the physical problem using the finite differences method. This implies the discretization of the barrel geometry into elements whose minimum size is determined by CESA´s engineers.

Having obtained the mathematical model, a parallel code to solve efficiently the problem was written, whose relevance lies in its speed. A modern workstation would spend a whole week to test a geometry, so the problem must be solved using parallelism to save time. A parallel algorithm was implemented on the group´s SGI PowerChallenge in Cantabria. Its SMP architecture allows a shared memory programming model using FORTRAN 77 with compilation directives to programme the parallel sections.

Within the project, the Power Challenge and the Origin 2000 at CEPBA have been used in order to test the application's scalability; additionally, the IBM SP2 at CESCA has analysed a message passing version of the code. Glasspar is the only complete environment for design, analysis and verification known in the industrial glass production field, as other world producers conceal their improvements. The research group is facing up the implementation of a MPI version in order to maximize portability; it could be run in shared memory computers, in networks of workstations and even in Pentium PC networks using Linux and Myrinet. The final objective is to show that parallelism is a good and cheap option for enterprises that need large amounts of calculation.

Monica Tudela